1. Field of the Invention
The present invention relates to an image processing apparatus for processing a monochromatic image with gradation or a color image.
2. Related Background Art
There is already known a method for stabilizing image, as disclosed in U.S. Pat. No. 4,888,636 and U.S. patent application Ser. No. 07/760,505, filed Sep. 16, 1991, by forming a characteristic pattern on an image bearing member, reading the density of said pattern and effecting feedback control on the supply amount of toner or on the image forming conditions based on the thus obtained density.
However, such conventional method is associated with a drawback that the faithful feedback of the read pattern density on the image forming conditions may result, depending on the control amount, in a discontinuity in gradation.
More specifically, in the preparation of a tonal correction table, if the density slope is too steep in the low density area, pseudo-contour is generated in a highlight area such as a human skin.
Also there has not been an apparatus that allows the operator to easily recognize the correction characteristics in the tonal correction.